


Sedimentation

by Kawaiibooker



Series: A Theory of Piracy [3]
Category: One Piece
Genre: (it's sabo), Alabasta, Brotherhood, Family Feels, Gen, Introspection, Reunions, i'm still emo about the ASL brothers but what else is new, references to (presumed) character death
Language: English
Status: Completed
Published: 2020-04-03
Updated: 2020-04-05
Packaged: 2021-02-22 21:21:34
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,531
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23467258
Author URL: https://archiveofourown.org/users/Kawaiibooker/pseuds/Kawaiibooker
Summary: sed·i·men·ta·tion(n.)The process of establishing and reinforcing meaning through repetition.*First and foremost, Ace is a big brother - not the only one Luffy's ever had, but the one he has left.
Relationships: Monkey D. Luffy & Portgas D. Ace, Monkey D. Luffy & Portgas D. Ace & Sabo, Mugiwara Kaizoku | Strawhat Pirates & Portgas D. Ace
Series: A Theory of Piracy [3]
Series URL: https://archiveofourown.org/series/1682008
Comments: 32
Kudos: 266





	1. Chapter 1

**Author's Note:**

> Set around Chapter 159: "Come On".

**Notes for the Chapter:**

> Unbetaed.

Even for a man made of fire, Alabasta is an uncomfortably warm place to be. The ground is arid to the point every step will kick up dust, and a fine haze of sand lingers in the air that turns the horizon into an indistinct flickering mess and makes every swallow rasp in the throat with grit.

From his vantage point high above, Ace slouches with his legs hanging off the ledge of a flat-roofed house and lets his gaze roam the streets below. His unknowing hosts bumble about downstairs, the muffled sounds of banging pots and laughter announcing it’s time for lunch; for a moment, Ace holds his stomach that rumbles a complaint, loud and insistent.

 _Just a little longer_ , he promises himself.

Not a single cloud graces the sky with its presence and the population below with a modicum of shade. Nanohana is a ghost town at noon, its inhabitants fleeing into their homes for a nap until the weather outside stops actively trying to cook them alive. Things didn’t use to be this bad – at least, from what Ace can recall of his first trip here, back when he was still captain of the Spade Pirates – but a lot can happen in three years.

Ace pulls his lips into a pout, the heat immediately stealing whatever moisture is left on them. No sign of Monkey D. Luffy.

Fingers drumming a tuneless beat against the brim of his hat, Ace _thinks_. Perhaps it had been a little foolish to assume Luffy would show up just like that, much less anywhere within the spectrum of ‘on time’. Even this early into the Grand Line, the waves are tricksters and the currents are more likely to lead to ruin than to any expectable outcome. Still: There had been rumors of a rookie crew demolishing Whisky Peak mere weeks ago, and a bombshell report out of the kingdom of Drum announced the rather violent eviction of its current (now former) ruler. Ace frowns, remembering the state of things he witnessed himself not too long ago.

_Good fucking riddance._

Well, Ace has always figured the day his little brother sailed across Reverse Mountain would be followed by chaos and destruction all around. With the world tilting on its axis and spinning more and more out of control with every passing day, it’s hard to say how it’s going to look like a month down the road, a year, two. The powers that be aren’t ready for someone like Luffy, not that Luffy would particularly care about that.

A fond chuckle bursts out of him at the thought. Whatever happens, Ace can't wait to see where all of it is headed.

 _First things first._ Ace flicks his hat back on his head and gets up, patting sand off his shorts. It’s _everywhere_ , stuck to his lashes and making the sweat on his back feel tacky and gross. He sighs. Shower first, then food. His meal will taste all the better knowing the tattoo of Father’s jolly roger is as it should be: untainted and shown off with pride.

And then, with some luck, he will finally be able to see his brother again.

*

Getting cannonballed into by 140 pounds of rubber is quite an experience, no matter how many times one has been subjected to it. On instinct, Ace’s arms shoot out to grab on to whichever piece of Luffy’s clothes he can reach and he turns in a lazy half-circle, automatically aligning his center of gravity around the excited bundle of limbs clinging to his head. It makes breathing an impossibility for a moment or five but it’s worth it every single time.

“Ace! It’s really you!”

“Hello to you too, Lu”, Ace laughs, his grin almost as toothy as his brother’s now that they can enjoy their reunion in peace and sans Marine meddling. In a play as old as time itself, Luffy settles with his legs bracketing Ace’s shoulders and his head firmly planted on–

“Oh! You still have your hat, too!”

–the top of his hat, chin nudging its crown into a more comfortable position with surprising gentleness. Ace can’t see the smile on Luffy’s face like this but he knows it’s there judging by the way dumbfounded astonishment morphs into fondness on the faces of his crew members.

Bowing as politely as he can, he smiles and says: “Portgas D. Ace, Second Division Commander of the Whitebeard Pirates... and Luffy’s brother. Nice to finally meet you.”

Among the sputtering of “Whitebeard? _The_ Whitebeard?” and “Wait, _brother_?!”, a guy with green hair and three swords makes the fastest recovery from general disbelief. He nods at Ace and smirks, “Likewise”, voice heavy with a confidence that rivals Luffy’s own. Seems like he’s the oldest in the bunch, too, which isn’t saying much since they all look about Luffy’s age and– _Is that a reindeer?_

(It’s hard to tell as whoever it is currently is trying to hide behind the main mast, ‘trying’ being the key word.)

They’re all strong though, Ace can tell. Inexperienced and fresh-faced and full of potential, just like their captain. His smile only grows.

_So this is Luffy’s crew._

“Oi Luffy, when were you gonna tell us you have a brother?”

Happily wriggling his feet against Ace’s stomach, Luffy _hmm_ s as if deep in thought. “Dunno!” is the answer he comes up with after careful consideration, and Ace chuckles along with some of the crew. “It never came up, you know? Ace has his own adventures and stuff.”

If the heat was tough before, it’s unbearable now with Luffy’s furnace of a body compounding the issue. Ace lets him stay, stepping on his brother’s ship with a murmured “May I?” and a quick nod from a woman with short, red hair. The caravel is small but charming and _cozy_ , so much so Ace feels immediately at ease. One of the many worries nipping at his nerves ever since he saw the name Strawhat Luffy under the words DEAD OR ALIVE is laid to rest then and there.

“Hey Ace, what are you doing here anyways?”

By now Luffy’s practically humming with unspent energy; Ace sighs and unceremoniously dumps him on deck, fixing his lopsided hat and necklace smoothly. Luffy is undeterred, snickering and effortlessly climbing a few feet up the mast to look at his brother from there.

“Taking care of business”, Ace answers casually yet can’t help the way his smile slips a little. The memory of Thatch bleeding out in his arms is too fresh, too grim to repress entirely. Luffy’s head tilts to the side but Ace waves him away before he can ask.

“Don’t worry, I can handle it. I just figured if I’m already around these parts I might as well meet up with my baby brother.”

When he left that message on Drum, Ace had figured he’d just say hi to his brother, tell his crew to watch over him ( _or else_ ) and be on his merry way to put down Blackbeard like the mangy fratricidal dog he is. It’s only after he’s successfully ticked off the second item on that list – the crew looks sufficiently humbled and that green-haired dude Zoro grins at him, clearly approving, and why does Ace feel like he just passed some sort of test? – that he finally realizes he didn't account for one thing in this brilliant plan of his.

Because his brother is _Luffy_ , and the moment Ace makes to leave he finds himself the target of a kicked-puppy-look-of-doom so heart-rending he feels terrible for even thinking that way.

“Lu, c’mon now, I…”

“But Ace! It’s been _three years_ and so much has happened and we just met and–”

And that’s that. The whiny note in Luffy’s voice effectively shreds through whatever resistance Ace has left (which, if he’s honest with himself, wasn’t much to begin with). At the end of the day, he _missed_ his little brother and it’s not like life hasn’t taught him – over and over and over again – to cherish the fleeting moments he has with those he loves. Ace pinches the bridge of his nose and groans.

“ _Fine_. One night, okay? _One_. I really have to go after that.”

Luffy cheers, gloom immediately forgotten, and it’s then that Ace notices his crew is breathing a sigh of relief, too. So they're already aware a sad Luffy is to be avoided at all costs. _Good._

The blonde one – Sanji the cook, Ace reminds himself – asks him what he’d like to eat and without thinking he says, “Anything with jolokia in it”, and Sanji shrugs, “Alright, coming right up”, and strolls away in the direction of the galley before it crosses Ace’s mind that those peppers are really hard to find _and_ he’s already had lunch just an hour prior. He distinctly remembers Luffy eating his weight at the bar earlier, too, and _he_ is yelling for meat at the top of his lungs.

 _Oh well._ Might as well try out Luffy’s cook and see for himself that his gluttonous brother is well cared f–

Someone clears their throat to draw his attention. “Mr. Portgas”, a woman says, voice pleasant and measured in a way only diplomats speak. On _this_ ship, with _that_ captain, finding someone so eloquent is the thing that ends up surprising Ace the most.

“Ace, please. What's the matter?”

She smiles, an obvious appreciation for his manners even if it doesn’t pierce through the troubled look swirling in her eyes. “Ace, sorry. I'm Vivi, then. Would you mind if we continue along the coast and up the river during the night? We, um, we have somewhere to be and time is of the essence.”

Ace blinks. _Isn’t that a question for your captain?_ Then again, Luffy is currently busy hounding his cook for scraps and knowing him, he’s not really the authoritarian type anyways, captain or no. 

“Uh. I don’t really care, I can set off from wherever with Striker.”

Vivi follows the gesture he makes to his trusty fire-powered speed boat but her interest is polite, half-hearted at best. “I see. I appreciate it, thank you.”

 _Not we but I, huh?_ Be it paranoia or justified caution, Ace knows the devil is in the details and this Vivi, she has something to hide. Yet nothing disturbs the air of trust the others seem to place in her: A secret kept only from strangers, then.

“A-ceee.”

Ah. Ace shakes himself out of the analytical stare he’s fixed her with, and to Vivi’s credit she merely locks her jaw and stares back, all pretense stripped to reveal a core of steely determination underneath. Luffy is pouting at him, draped across the railing of the forecastle and clearly unhappy with the subtle tension rising around them.

“Stop being all serious and come here, I want you to meet Merry!”

Scratching his neck, Ace huffs a breath – “Alright, jeez. Give me a second.” – and he nods at Vivi, both an apology and a concession to what they discussed. “Let me know if I can help with… whatever’s going on. It sounds important.”

The smile she gives him is more genuine, this time. “It is. You’ve already done enough keeping the Marine off our backs, though.”

Ace shrugs, _have it your way_ , and before Luffy can start getting annoying for real, he launches himself in a column of fire to his brother’s side. “Okay, then. Who’s this Merry?”

**Notes for the Chapter:**

> Ace waiting around in Alabasta:
> 
> This was more of a warmup for chapter 2, coming soon. I know the anime had some filler episodes with Ace in it but uh, this is about something else. You'll see.
> 
> But yeah, Ace. Remember when we all read the Alabasta arc and _didn't_ feel soul-crushing despair seeing this guy smile and be happy? Yeah... I miss him so much y'all :(


	2. Chapter 2

**Notes for the Chapter:**

> Beta-read by [Pitte](https://twitter.com/PPitteArt).

The Strawhats truly are a crazy bunch and Ace is _fascinated_. It didn’t take long at all for Sanji to bust out of the kitchen with a mouth-watering amount of food, and Luffy disappears from Ace’s side so fast he basically teleports.

Shaking his head, Ace climbs down the stairs leading up to Merry’s figurehead at a more measured pace, watching the crew deal with his brother’s antics like it’s nothing, as easy as breathing. Hands fly and insults right along with them as they somehow wrangle him into sitting down properly and keeping to his own plate (for the most part) and Luffy _does_ , beaming bright as the sun in their midst.

It softens something in Ace’s heart to witness it – Luffy has grown in the time they spent apart, stronger in many ways and mellowed out in others and unchanged where it matters. Perhaps his crew doesn’t realize it yet but it’s no small feat, to accept him just as he is.

Then, a rubbery arm wraps around Ace’s waist and he’s pulled (literally rather than figuratively) into the fray.

Lunch is a loud and boisterous affair. Ace gives as good as he gets, fighting for every delicious bite from where he’s squeezed in-between Luffy and a guy as gangly and awkward as they come, and he can’t remember a time he saw devastation quite like when Usopp dares him to try his Tabasco Shot and it does absolutely nothing.

“I fried my sense for spicy food years ago”, Ace admits between peals of laughter. Usopp’s eyes light up before he scrambles to his little workshop haphazardly placed in the middle of the deck.

“Don’t go anywhere! You’re my test subject now!”

It’s a good while later that things start to settle down on the Going Merry as she makes her way up the Sandora River. One by one, the Strawhats disperse to their own corners of the ship, clearing out the mess left behind and cycling through their duties without a single input from their captain – be it by design or implicit understanding, it’s hard to tell. And while Luffy is all-too-happy to hog his brother’s attention, Ace soaks up the obvious joy radiating from his voice and the unique cadence of his laughter.

Crouching on one of Merry’s horns, head pillowed on the palm of his hand, he lets himself be regaled by story after story of their adventures, told in that nonsensical style of narration Ace knows better than his mother tongue. Luffy sprawls all over his ship’s figurehead like it’s an extension of his body, hands a blur as he acts out what he means with gestures and grimaces.

For being a crew from what is considered the weakest Blue, the Strawhat Pirates have caused quite the stir. Ace smirks. _About time people stopped underestimating the underdogs._

After all, his mouth still burns from the final rendition of Usopp’s self-made tabasco, one the sniper declared as his new weapon with a glint of triumph in his eyes.

It dawns on him, as Luffy imitates climbing with clawed fingers and a short-lived scowl on his face (“–it was _so_ high, Ace, and there was ice everywhere and no more bunnies to help us, you know? And then–”), that Monkey D. Luffy is a good captain. It’s not a lack of faith in Luffy’s abilities or a big brother’s sense of superiority that ever put that into question: The truth is that Luffy is trusting and kind-hearted to a fault, the devotion to his friends easily spanning all oceans and beyond.

Absolute loyalty, rare as it is in this jaded world, is one hell of a double-edged sword to fight your battles with, and the Strawhats strive for it with the same fervor as the dreams they wrote across their hearts and souls.

It’s the same brand of recklessness that nearly got the Spade Pirates killed, back when Father was still Whitebeard, one of the Four Emperors, and Ace had a personal vendetta against the universe itself (and the man it called King) to carry out.

History has a nasty habit of repeating itself, of transmitting a sin from father to child and brother to brother, and Ace hadn’t known _shit_ about that when they’d raised their cups of sake that day and swore to be family until the end.

Yet here Luffy is, giving out pieces of his heart and expecting everyone to fall into step beside him. Even their current quest across Alabasta seems to be driven by some favor or other – keeping a low profile, for one, seems completely antithetical to the small crew made large by their personalities – and Ace _worries_.

It's in moments like these that he wishes he wasn’t the only big brother Luffy has left.

“Ace?”

Luffy’s eyes are big and serious, hands having come to rest on his knees and brows drawing into a pensive line while Ace was lost in his head. It’s second nature to join him then, cross-legged and close enough to brush shoulders.

“What is it?”, Ace asks quietly as he takes off his hat, lets it spin between his fingers – he offers it to Luffy, “Here”, a soft smile sneaking on his lips as his brother takes it and starts toying with it.

The distraction doesn’t work as well as it used to, and that’s alright. The main point is that, even as a kid, having something to keep his hands busy always helped Luffy parse through the thoughts bouncing around in his head.

Then, finally: “Where’s White-guy? He’s your captain, right?”

The questions are unexpectedly solemn, and Ace raises his eyebrows, waits for Luffy to elaborate. There’s a frustrated twist to his brother’s mouth, something small and annoyed.

“Like… It’s not fair. Does he know you’re all alone out here?”

Just like that, the pieces rearrange in Ace’s mind to produce a whole, and yeah, that _would_ be a fault in Luffy’s eyes. “Hm, I get what you mean. Father…” Ace sighs. _Where to begin?_

“Every captain is different, and for him, we’re his sons. There was– Someone killed one of his sons, one of _us_ , and Father didn’t want me to go after him but I insisted. It’s as if I tried to kill you, or you me. It’s unforgiveable, you see? So that’s why I’m here – I’m gonna bring that fucker to justice.”

A fraction of the anger seething within him seeps into Ace’s voice and it’s been years since he let himself be driven by hatred like this. But Luffy, he’s known Ace from a time everything that came out of his mouth was laced with lethal intent, and spite was all he knew how to reach for.

There is no unease in Luffy’s gaze now either, and when he returns Ace’s hat to him, his hands are steady and unbothered by hesitation.

“That won’t happen. Why would I want to kill you?”

Luffy says it with such earnestness, like he couldn’t come up with a single reason if given a hundred years to think about it; Ace laughs and puts his hat back on his head, and love surges through him like the fire in his veins.

“Exactly. It shouldn’t.”

“So your new dad is a good guy after all?”

“He’s the _best_ ”, Ace says with a conviction he feels down to his bones, and Luffy smiles right along with him. “I want you to meet him someday, Lu, you and your crew. I don’t think I can change your mind about who should be Pirate King–”

“ _Never_.”

“–but you’ll like him. And you could meet my crew, too. _And_ our flag ship looks like a whale. A big white one.”

“Really? That’s cool!”

“Right?!”

They laugh just as they used to whilst pretending to sleep at night, hushed and with their heads bowed close to each other as if to fit under the same blanket. It’s quiet for a while, afterwards, Ace listening to the lapping of the waves against wood and watching the cloudless sky go by and Luffy watching _him_.

Ace guesses he’s thinking of his inevitable departure tomorrow but there is little he can do about that. Even as his big brother, Ace can’t protect Luffy from everything in life.

The touch to his shoulder comes a bit sudden and Ace almost jumps, takes in the pensive look on Luffy’s face and then the careful motion of his finger as he traces heavy, inked lines: Gently, he writes _A_ , then _C_ , then _E_ , and returns upwards to brush over the crossed-out _S_ with his thumb.

“Do you think he’d be proud of us?”

Ace hums, glances down at the tattoo. It had been the first thing he’d gotten with his own money – paid with treasure, Sabo would’ve loved that – and it’s a little faded now but it still fills Ace with determination, to know Sabo is with him and his memory will continue to exist as long as Ace draws breath.

“Sabo? Yeah, I think so. He’d be happy we kept our deal and sailed out to sea.” Ace chuckles, rubbing his shoulder fondly. “Perhaps a little miffed that I’m _definitely_ the oldest brother now but, well. What do you think?”

“Mhm, I think so too. And we’re free now, right? Just like we said.”

“Yeah. We are.”

Luffy huffs a laugh, leaning back against Merry and linking his arms behind his head like he doesn’t have a care in the world. _No regrets, huh, Sabo?_ Ace’s chest feels warm with nostalgia and he makes himself comfortable, too, gazing towards the sea and imagining Sabo sailing ahead of them, eyes fixed on the horizon and his flag waving proudly in the wind.

_We promised, after all._

**Notes for the Chapter:**

> I realized the other day what Ace's tattoo really means and after cursing Oda to high heaven (as you do), I sat down to write this. Thinking about how Ace died without knowing Sabo _lived_ hurts me to this day, so I wanted him to be at peace with that loss at least. It's the small things in life? :(
> 
> (Also I might write a fic specifically for Luffy & Sabo at some point 'cause that's another can of feels-worms I have to open eventually hahaha)

**Author's Note:**

> [tumblr](https://kawaiibooker.tumblr.com) / [twitter](https://twitter.com/kawaiibooker)


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